docs: def search(self, index, query):
          """
          Begin a map/reduce operation using a Search. This command will
          return an error unless executed against a Riak Search cluster.
  
          :param index: The Solr index used in the search
          :type index: string
          :param query: The search query
          :type query: string
          :rtype: :class:`RiakMapReduce`
          """
          self._input_mode = 'query'
          self._inputs = {'bucket': index,
                          'index': index,
                          'query': query}
          return self